U.S. patent number 10,542,978 [Application Number 13/117,410] was granted by the patent office on 2020-01-28 for method of internally potting or sealing a handheld medical device.
This patent grant is currently assigned to Covidien LP. The grantee listed for this patent is Xingrui Chen, Matthew Chowaniec, Michael Zemlok. Invention is credited to Xingrui Chen, Matthew Chowaniec, Michael Zemlok.
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United States Patent |
10,542,978 |
Chowaniec , et al. |
January 28, 2020 |
Method of internally potting or sealing a handheld medical
device
Abstract
The present disclosure provides a powered surgical instrument
including a housing defining an inner cavity therein; at least one
internal component disposed within the housing; and potting
material injected into the inner cavity encapsulating at least a
portion of the at least one internal component.
Inventors: |
Chowaniec; Matthew (Middletown,
CT), Chen; Xingrui (Hamden, CT), Zemlok; Michael
(Prospect, CT) |
Applicant: |
Name |
City |
State |
Country |
Type |
Chowaniec; Matthew
Chen; Xingrui
Zemlok; Michael |
Middletown
Hamden
Prospect |
CT
CT
CT |
US
US
US |
|
|
Assignee: |
Covidien LP (Mansfield,
MA)
|
Family
ID: |
46149295 |
Appl.
No.: |
13/117,410 |
Filed: |
May 27, 2011 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20120303002 A1 |
Nov 29, 2012 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B
17/07207 (20130101); A61B 2017/00128 (20130101); A61B
2017/00017 (20130101); A61B 2017/2927 (20130101); A61B
2017/00734 (20130101); A61B 2090/0813 (20160201); A61B
2017/00398 (20130101); A61B 2017/00115 (20130101) |
Current International
Class: |
A61B
17/00 (20060101); A61B 17/072 (20060101) |
Field of
Search: |
;29/527.1-527.4,611,841 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
0157936 |
|
Oct 1985 |
|
EP |
|
1115105 |
|
May 1968 |
|
GB |
|
WO 96/10957 |
|
Apr 1996 |
|
WO |
|
WO 2007/002180 |
|
Jan 2007 |
|
WO |
|
Other References
European Search Report for EP 12169440.0-2310 date of completion is
Aug. 23, 2012 (9 pages). cited by applicant .
EPO-TEK 377H Technical Data Sheet, Jan. 31, 2007, pp. 1-1,
XP55035972, retrieved from the Internet: URL:
http://www.epotek.com/sscdocs/datasheets/377h.pdf [retrieved on
Jan. 2002], * "graphite filled epoxy", "ESD/EMI shielding of
semiconductor devices and electronics".* cited by applicant .
Extended European Search Report for appln. No. 16189711.1 dated
Feb. 8, 2017. cited by applicant .
Anonymous: "Resin dispensing--Wikipedia", Wikipedia, Nov. 6, 2010
(Nov. 6, 2010), pp. 1-6, XP055339617, Wikipedia retrieved from the
Internet:
URL:https://en.wikipedia.org/w/index.php?title=Resin_dispensing&oldid=395-
243833#Sealing_of_electronic_parts [retrieved on Jan. 27, 2017]
*Chapter 8.1 Sealing of electronic parts*. cited by applicant .
Canadian Office Action dated Apr. 25, 2018 issued in corresponding
Australian Appln. No. 2,776,740. cited by applicant.
|
Primary Examiner: Abreu; Michael J D
Attorney, Agent or Firm: Carter, DeLuca & Farrell
LLP
Claims
What is claimed:
1. A method for manufacturing a powered surgical device, the method
comprising: sealing a housing of the powered surgical device, the
housing defining a cavity therein; injecting a liquid potting
material including an electro-magnetic field shielding additive in
an amount from about 16% to about 90% by weight of the liquid
potting material into the cavity of the sealed housing to
hermetically seal the housing, cavity including: a motor disposed
within the cavity; a light emitting diode disposed within the
cavity: an electrical switch disposed within the cavity that is
configured to cause the motor to actuate jaws of an end effector
coupled to the housing; and at least one additional internal
component disposed within the cavity; and solidifying the potting
material to encapsulate the light emitting diode and at least a
portion of the motor, at least a portion of the electrical switch,
and at least a portion of the at least one internal component,
wherein the potting material is substantially transparent.
2. The method according to claim 1, wherein the potting material
includes at least one additional additive selected from the group
consisting of a thermally conductive additive, a dielectric
additive, and combinations thereof.
3. The method according to claim 2, wherein the thermally
conductive additive is selected from the group consisting of
abrasive ceramics, lubricious ceramics, boron nitride, aluminum
oxide, aluminum nitride, and combinations thereof.
4. The method according to claim 1, wherein the potting material is
a polymer selected from the group consisting of polyesters,
silicones, rubbers, epoxies, nylons, polyphthalamides, liquid
crystal polymers, and combinations thereof.
5. The method according to claim 1, wherein the electro-magnetic
field shielding additive is selected from the group consisting of
ferrous compounds, nickel-based compounds, carbon-based conductive
fibers, carbon-based conductive particles, and combinations
thereof.
Description
BACKGROUND
Technical Field
The present disclosure relates to a powered surgical instrument
having housing enclosing a plurality of internal components,
including a drive mechanism and a control circuit. More
particularly, the present disclosure relates to a surgical
instrument including internal components that are encapsulated in a
potting material within the housing.
Background of Related Art
Surgical devices wherein tissue is first grasped or clamped between
opposing jaw structure and then joined by surgical fasteners are
well known in the art. In some instruments a knife is provided to
cut the tissue which has been joined by the fasteners. The
fasteners are typically in the form of surgical staples but two
part polymeric fasteners can also be utilized.
Instruments for this purpose may include two elongated members
which are respectively used to capture or clamp tissue. Typically,
one of the members carries a staple cartridge which houses a
plurality of staples arranged in at least two lateral rows while
the other member has an anvil that defines a surface for forming
the staple legs as the staples are driven from the staple
cartridge. Generally, the stapling operation is effected by cam
bars that travel longitudinally through the staple cartridge, with
the cam bars acting upon staple pushers to sequentially eject the
staples from the staple cartridge. A knife can travel between the
staple rows to longitudinally cut and/or open the stapled tissue
between the rows of staples.
In endoscopic or laparoscopic procedures, surgery is performed
through a small incision or through a narrow cannula inserted
through small entrance wounds in the skin. In order to address the
specific needs of endoscopic and/or laparoscopic surgical
procedures, endoscopic surgical stapling devices have been
developed.
Current known devices can typically require 10-60 pounds of manual
hand force to clamp tissue and deploy and form surgical fasteners
in tissue which, over repeated use, can cause a surgeon's hand to
become fatigued. Gas powered pneumatic staplers which implant
surgical fasteners into tissue are known in the art. Certain of
these instruments utilize a pressurized gas supply which connects
to a trigger mechanism. The trigger mechanism, when depressed,
simply releases pressurized gas to implant a fastener into
tissue.
Motor-powered surgical staplers are also known in the art. These
include powered surgical staplers having motors which activate
staple firing mechanisms. However, these motor powered devices also
include a variety of internal components (e.g., circuits) which
require additional protection from moisture, chemical cleaners,
vapors, gases, and biological contaminants. There is a continual
need for new and improved powered surgical staplers which provide
protection to the internal components.
SUMMARY
The present disclosure provides a powered surgical instrument
including a housing defining an inner cavity therein; at least one
internal component disposed within the housing; and potting
material injected into the inner cavity encapsulating at least a
portion of the at least one internal component.
The present disclosure also provides a method for manufacturing a
powered surgical device. The method includes injecting a liquid
potting material injected into a housing defining an inner cavity
therein, the housing including at least one internal component
disposed within the housing; and solidifying the potting material
to encapsulate at least a portion of the at least one internal
component.
The present disclosure further provides a powered surgical
instrument. The instrument includes a housing defining an inner
cavity therein, the housing including a handle portion; a body
portion extending distally from the handle portion; a tool assembly
disposed at a distal end of the body portion; a control circuit and
a drive motor disposed within the inner cavity, wherein the drive
motor is mechanically coupled to the tool assembly and the control
circuit is configured to control the operation of the drive motor;
and a potting material injected into the inner cavity encapsulating
at least a portion of at least one of the control circuit and the
drive motor.
BRIEF DESCRIPTION OF THE DRAWINGS
Various embodiments of the subject instrument are described herein
with reference to the drawings wherein:
FIG. 1 is a perspective view of a powered surgical instrument
according to the present disclosure;
FIG. 2 is a partial enlarged perspective view of the powered
surgical instrument according to the embodiment of the present
disclosure of FIG. 1 according to the present disclosure;
FIG. 3 is a partial enlarged plan view of the powered surgical
instrument according to the embodiment of the present disclosure of
FIG. 1 according to the present disclosure; and
FIG. 4 is a partial perspective sectional view of internal
components of the powered surgical instrument of FIG. 1 according
to the present disclosure.
FIG. 5 is a flowchart of an embodiment of a method of injecting
potting material according to the present disclosure.
DETAILED DESCRIPTION
Embodiments of the presently disclosed powered surgical instrument
are now described in detail with reference to the drawings, in
which like reference numerals designate identical or corresponding
elements in each of the several views. As used herein the term
"distal" refers to that portion of the powered surgical instrument,
or component thereof, farther from the user while the term
"proximal" refers to that portion of the powered surgical
instrument or component thereof, closer to the user.
A powered surgical instrument, e.g., a surgical stapler, in
accordance with the present disclosure is referred to in the
figures as reference numeral 10. Referring initially to FIG. 1,
powered surgical instrument 100 includes a housing 110, an
endoscopic portion 140 defining a first longitudinal axis A-A
extending therethrough, and an articulating tool assembly (e.g.,
end effector 160), defining a second longitudinal axis B-B
extending therethrough. Endoscopic portion 140 extends distally
from housing 110 and the end effector 160 is disposed adjacent a
distal portion of endoscopic portion 140. In an embodiment, the
components of the housing 110 are sealed against infiltration of
particulate and/or fluid contamination and help prevent damage of
the components by sterilization processes. The instrument 100 also
includes a power source 300
According to an embodiment of the present disclosure, end effector
160 includes a first jaw member having one or more surgical
fasteners (e.g., cartridge assembly 164) and a second opposing jaw
member including an anvil portion for deploying and forming the
surgical fasteners (e.g., an anvil assembly 162). In certain
embodiments, the staples are housed in cartridge assembly 164 to
apply linear rows of staples to body tissue either in simultaneous
or sequential manner. Either one or both of the anvil assembly 162
and the cartridge assembly 164 are movable in relation to one
another between an open position, in which the anvil assembly 162
is spaced from cartridge assembly 164, and an approximated or
clamped position, in which the anvil assembly 162 is in juxtaposed
alignment with cartridge assembly 164.
It is further envisioned that end effector 160 is attached to a
mounting portion 166, which is pivotably attached to a body portion
168. Body portion 168 may be integral with endoscopic portion 140
of powered surgical instrument 100, or may be removably attached to
the instrument 100 to provide a replaceable, disposable loading
unit (DLU) or single use loading unit (SULU) (e.g., loading unit
169). In certain embodiments, the reusable portion may be
configured for sterilization and re-use in a subsequent surgical
procedure.
The loading unit 169 may be connectable to endoscopic portion 140
through a bayonet connection. It is envisioned that the loading
unit 169 has an articulation link connected to mounting portion 166
of the loading unit 169 and the articulation link is connected to a
linkage rod so that the end effector 160 is articulated as the
linkage rod is translated in the distal-proximal direction along
first longitudinal axis A-A. Other means of connecting end effector
160 to endoscopic portion 140 to allow articulation may be used,
such as a flexible tube or a tube comprising a plurality of
pivotable members.
The loading unit 169 may incorporate or be configured to
incorporate various end effectors, such as vessel sealing devices,
linear stapling devices, circular stapling devices, cutters,
graspers, etc. Such end effectors may be coupled to endoscopic
portion 140 of powered surgical instrument 100. An intermediate
flexible shaft may be included between handle portion 112 and
loading unit. It is envisioned that the incorporation of a flexible
shaft may facilitate access to and/or within certain areas of the
body.
With reference to FIGS. 1 and 2, an enlarged view of the housing
110 is illustrated according to an embodiment of the present
disclosure. In the illustrated embodiment, housing 110 includes a
handle portion 112 having a main drive switch 114 disposed thereon.
The switch 114 may include first and second switches 114a and 114b
formed together as a toggle switch. The handle portion 112, which
defines a handle axis H-H, is configured to be grasped by fingers
of a user. The handle portion 112 has an ergonomic shape providing
ample palm grip leverage which helps prevent the handle portion 112
from being squeezed out of the user's hand during operation. Each
switch 114a and 114b is shown as being disposed at a suitable
location on handle portion 112 to facilitate its depression by a
user's finger or fingers.
Additionally, and with continued reference to FIGS. 1 and 2,
switches 114a, 114b may be used for starting and/or stopping
movement of a drive mechanism (e.g., drive motor 200) (FIG. 4). The
drive motor 200 is configured to actuate the end effector 160,
including but not limited to, articulation, closing of the jaw
members, ejection of fasteners, cutting, and the like. In one
embodiment, the switch 114a is configured to activate the drive
motor 200 in a first direction to advance firing rod (not
explicitly shown) in a distal direction thereby approximating the
anvil and the cartridge assemblies 162 and 164. Conversely, the
switch 114b may be configured to retract the firing rod to open the
anvil and cartridge assemblies 162 and 164 by activating the drive
motor 200 in a reverse direction. The retraction mode initiates a
mechanical lock out, preventing further progression of stapling and
cutting by the loading unit 169. The toggle has a first position
for activating switch 114a, a second position for activating switch
114b, and a neutral position between the first and second
positions. Further, the switches 114a and 114b may have high
tactile feedback requiring increased pressure for activation.
In one embodiment, the switches 114a and 114b are configured as
multi-speed (e.g., two or more), incremental or variable speed
switches which control the speed of the drive motor 200 and the
firing rod in a non-linear manner. For example, switches 114a, 114b
can be pressure-sensitive. This type of control interface allows
for gradual increase in the rate of speed of the drive components
from a slower and more precise mode to a faster operation. To
prevent accidental activation of retraction, the switch 114b may be
disconnected electronically until a fail safe switch 114c is
pressed.
The switches 114a and 114b are coupled to a non-linear speed
control circuit 400 which may include a non-linear speed control
circuit implemented as a voltage regulation circuit, a variable
resistance circuit, or a microelectronic pulse width modulation
circuit. The switches 114a and 144b may interface with the control
circuit 400 by displacing or actuating variable control devices,
such as rheostatic devices, multiple position switch circuit,
linear and/or rotary variable displacement transducers, linear
and/or rotary potentiometers, optical encoders, ferromagnetic
sensors, and Hall Effect sensors. This allows the switches 114a and
114b to operate the drive motor 200 in multiple speed modes, such
as gradually increasing the speed of the drive motor 200 either
incrementally or gradually depending on the type of the control
circuit being used, based on the depression of the switches 114a
and 114b.
FIGS. 2-4 illustrate an articulation mechanism 170, including an
articulation housing 172, a powered articulation switch 174, an
articulation motor 132 and a manual articulation knob 176.
Translation of the powered articulation switch 174 or pivoting of
the manual articulation knob 176 activates the articulation motor
132 which then actuates an articulation gear 233 of the
articulation mechanism 170 as shown in FIG. 4. Actuation of
articulation mechanism 170 causes the end effector 160 to move from
its first position, where longitudinal axis B-B is substantially
aligned with longitudinal axis A-A, towards a position in which
longitudinal axis B-B is disposed at an angle to longitudinal axis
A-A. The powered articulation switch 174 may also incorporate
similar non-linear speed controls as the clamping mechanism.
Additionally, articulation housing 172 and powered articulation
switch 174 are mounted to a rotating housing assembly 180. Rotation
of a rotation knob 182 about first longitudinal axis A-A causes
housing assembly 180 as well as articulation housing 172 and
powered articulation switch 174 to rotate about first longitudinal
axis A-A, and thus rotating the end effector 160 about first
longitudinal axis A-A. The articulation mechanism 170 is
electro-mechanically coupled to one or more conductive rings that
are disposed on a housing nose assembly 155 (FIG. 4). The
conductive rings may be soldered and/or crimped onto the nose
assembly 155 and are in electrical contact with the power source
300 thereby providing electrical power to the articulation
mechanism 170. The nose assembly 155 may be modular and may be
attached to the housing 110 during assembly to allow for easier
soldering and/or crimping of the rings. The articulation mechanism
170 may include one or more brush and/or spring loaded contacts in
contact with the conductive rings such that as the housing assembly
180 is rotated along with the articulation housing 172 the
articulation mechanism 170 is in continuous contact with the
conductive rings thereby receiving electrical power from the power
source 300.
Further details of articulation housing 172, powered articulation
switch 174, manual articulation knob 176 and providing articulation
to end effector 160 are described in detail in commonly-owned U.S.
patent application Ser. No. 11/724,733 filed Mar. 15, 2007, the
contents of which are hereby incorporated by reference in their
entirety. It is envisioned that any combinations of limit switches,
proximity sensors (e.g., optical and/or ferromagnetic), linear
variable displacement transducers and shaft encoders which may be
disposed within housing 110, may be utilized to control and/or
record an articulation angle of end effector 160 and/or position of
the firing rod 220.
As shown in FIG. 4, the instrument 100 also includes the control
circuit 400 electrically coupled to the motor 200 and various
sensors disposed in the instrument 100. The sensors detect various
operating parameters of the instrument 100 (e.g., linear speed,
rotation speed, articulation position, temperature, battery charge,
and the like), which are then reported to the control circuit 400.
The control circuit 400 may then respond accordingly to the
measured operating parameters to control the actuation of the end
effector 160 (e.g., adjust the speed of the motor 200, control
articulation angle, shut-off the power supply, report error
conditions, etc.).
As shown in FIGS. 3 and 4, the control circuit 400 is also coupled
to one or more visual devices which may include one or more colored
visible lights or light emitting diodes 401 ("LED") to relay
feedback to the user. The LEDs 401 may disposed on top of the
housing 110 such that the LEDs 401 are raised and protrude in
relation to the housing 110 providing for better visibility thereof
as shown in FIG. 4. In embodiments, the LEDs 401 may be disposed
within the housing 110 as shown in FIG. 4. The LEDs 401 may be
activated in a various combinations to denote
The multiple lights may be activated in a certain combination to
illustrate a specific operational mode to the user. In one
embodiment, the LEDs 401 include a plurality of multi-colored
lights--a first light (e.g., yellow), a second light (e.g., green)
and a third light (e.g., red). The lights are operated in a
particular combination associated with a particular operational
mode as listed in Table 1 below.
TABLE-US-00001 TABLE 1 Light Combination Light Status Operational
Mode First Light Off No loading unit 169 or staple cartridge Second
Light Off is loaded. Third Light Off First Light On The loading
unit 169 and/or staple cartridge Second Light Off are loaded and
power is activated, allowing Third Light Off the end effector 160
to clamp as a grasper and articulate. First Light Flashing A used
loading unit 169 or staple cartridge Second Light Off is loaded.
Third Light Off First Light N/A Instrument 100 is deactivated and
prevented Second Light Off from firing staples or cutting. Third
Light N/A First Light On A new loading unit 169 is loaded, the end
Second Light On effector 160 is fully clamped and the Third Light
Off instrument 100 is in firing staple and cutting modes. First
Light On Due to high stapling forces a pulse mode is Second Light
Flashing in effect, providing for a time delay during Third Light
Off which tissue is compressed. First Light N/A No system errors
detected. Second Light N/A Third Light Off First Light On Tissue
thickness and/or firing load is too high, Second Light On this
warning can be overridden. Third Light On First Light N/A
Functional system error is detected, instrument Second Light N/A
100 should be replaced. Third Light Flashing
In another embodiment, the LEDs 401 may be multi-colored LEDs which
display a particular color associated with the operational modes as
discussed above with respect to the first, second and third lights
in Table 1.
The housing 110 defines an inner cavity 402 in which the control
circuit 400 and the motor 200 as well as other components of the
instrument 100 are disposed. With reference to FIG. 5, during step
S20, a potting material 404 is injected into the cavity 402 so that
the material flows into and through the cavity 402, thereby coating
and encapsulating the internal components (e.g., the control
circuit 400 and the motor 200) of the instrument 100. The material
404 may be injected such that the cavity 402 is either partially or
wholly filled with the material 404. Encapsulation of the internal
components eliminates voids within the inner cavity 402, which may
collect moisture and condensation. Further, the material 404 also
seals the components, thereby providing protection from moisture,
chemical compounds (e.g., cleaners), vapors, gasses, and biological
contaminants. This would also allow for sterilization of the
instrument 100 providing for multiple uses.
Prior to injecting the material 404 into the housing 110 during
step S20, the housing 110 may be suitably sealed during step S10 to
withstand pressures of the sealing process as well as to
hermetically seal the housing 110 as described above. The material
404 may be any material that may be any liquid or amorphous
material that solidifies upon injection into the cavity 402. In
embodiments, the material 404 may be any material or combination of
materials (e.g., epoxy) that may change its phase after injection
into the housing 110, such that the material 404 is initially in a
liquid phase and then transitions into a solid phase to encapsulate
the components. Once solidified during step S30, the material 404
may be relatively rigid to protect the components from shock,
maintain compliance and to reduce stress under temperature extremes
and other environmental conditions.
In embodiments, the material 404 may be a liquid material that may
be solidified by one of the following processes which include, but
are not limited to, room temperature vulcanization, a thermosetting
polymer reaction (e.g., epoxy), curing (e.g., anaerobic or
ultra-violet), and combinations thereof. The material 404 may be a
polymer, which may include, but not limited to, polyesters,
silicones, rubbers, epoxies, nylons, polyphthalamides, liquid
crystal polymers, and combinations thereof.
The material 404 once solidified may have a hardness as measured by
a durometer from about 5 Shore A to about 100 Shore A, in
embodiments from about 10 Shore A to about 50 Shore A. In
embodiments, the material 404 may be compliant and/or elastic. This
prevents high physical stress that the instrument 100 is subjected
to from being transferred to the internal components and/or in
embodiments where components or materials of the instrument 100
have discrepant thermal expansion properties. In addition,
elasticity of the material 404 absorbs noise and vibration
generated by the drive motor 200 and other drive mechanisms, which
enhances the handling characteristics of the instrument 100.
The material 404 may include one or more thermally conductive
and/or dielectric additives to draw thermal energy from the
components as well as to electrically isolate electronic and other
sensitive components (e.g., drive mechanisms, batteries, etc.). In
addition, material 404 that is thermally conductive also reduces
thermal shock and temperature extremes associated with
sterilization (e.g., autoclaving) processes. The material 404 may
have a thermal conductance from about 0.024 watts per meter.degree.
C. (W/m.degree. C.) and above. The material 404 may have an
electrical resistance from about 3 millivolts per meter under
standard temperature and pressure (STP) (mV/m) and above. The
material 404 may have a coefficient of thermal expansion from about
1 parts per million/.degree. C. (ppm/.degree. C.) to about 30
ppm/.degree. C., in embodiments from about 5 ppm/.degree. C. to
about 20 ppm/.degree. C. The material may have a surface energy
from about 10 dynes per centimeter.sup.2 (dynes/cm.sup.2) to about
45 dynes/cm.sup.2, in embodiments from about 20 dynes/cm.sup.2 to
about 35 dynes/cm.sup.2. The term "surface energy" as used herein
denotes the disruption of intermolecular bonds that occurs when a
surface is created expressed as pressure.
Suitable thermally conductive additives include, but are not
limited to, abrasive or lubricious ceramics, boron nitride,
aluminum oxide, aluminum nitride, and combinations thereof. The
material 404 may include the thermally conductive additive in
amount from about 0.5 to about 90% by weight of the material 404,
in embodiments, from about 5 to about 25% by weight of the material
404. The material 404 may also be substantially translucent,
transparent or combination thereof to allow the LEDs 401 to
transmit light therethrough such that the light transmitted by the
LEDs 401 is visible to the user.
The material 404 may also include an electro-magnetic shielding
additive. Suitable electro-magnetic shielding additives include,
but are not limited to metallic compounds, such as ferrous or
nickel-based compounds, as well as carbon-based conductive fibers
and powders, and combinations thereof. The material 404 may include
the electro-magnetically shielding additive in amount from about
0.5 to about 90% by weight of the material 404, in embodiments,
from about 5 to about 25% by weight of the material 404.
It will be understood that various modifications may be made to the
embodiments shown herein. Therefore, the above description should
not be construed as limiting, but merely as exemplifications of
preferred embodiments. Although specific features of the powered
surgical instrument are shown in some of the drawings and not in
others, this is for convenience only as each feature may be
combined with any or all of the other features in accordance with
the aspects of the present disclosure. Other embodiments will occur
to those skilled in the art and are within the following
claims.
* * * * *
References